FILE PHOTO: Test tubes are seen labelled "Bird Flu" words in this illustration taken, June 10, 2024. REUTERS/Dado Ruvic/Illustration/File Photo

By Tom Polansek

CHICAGO (Reuters) - Nebraska confirmed its first case of bird flu in a dairy cattle herd, the U.S. Department of Agriculture said on Monday, showing the virus continues to spread in livestock after an outbreak began last year.

Dairy cattle in 17 states have been confirmed to be infected since the start of the outbreak in March 2024, though reports of cases generally have slowed since last year, according to the USDA. California, Michigan, Nevada, Idaho, Arizona and Texas also reported cases in herds this year.

Infected cows often produce less milk, consume less feed and suffer other symptoms.

Bird flu viruses circulating in dairy cows and birds pose a low risk to the general public, according to the U.S. Centers for Disease Control and Prevention. Farm workers who come in contact with infected animals are more at risk.

Since 2024, the virus has infected 70 people, mostly workers on dairy farms, according to the CDC.

Pasteurized milk sold to consumers is safe because pasteurization has been shown to inactivate the virus, the USDA said in a statement.

The herd in Nebraska is located in the central part of the state and has been quarantined, according to the Nebraska Department of Agriculture.

The strain of the virus is similar to a strain from California, the top U.S. milk-producing state, which had a major outbreak last year and found more cases in 2025, the department said.

Nebraska is a major producer of cattle raised for beef, though bird flu has not been confirmed in U.S. beef cattle.

(Reporting by Tom Polansek; Editing by Sonali Paul)